Bag valve



June 1, 1965 c. J. EVENBLIJ BAG VALVE Filed Sept. 6. 1962 United States Patent 3,186,627 BAG VALVE Johan Carl Julius Evenblij, Koog aan de Zaan, Netherlands, assignor to Dutch Company Polypress N.V.,

69,052 3 Claims. (CL 229-625) The inventon relates to abag, and in particular =to a bag provided with an inernal flexible filling tube which is closed ol by the pressure of the filling material during the filling procws, and which is attached to the bag in such manner that its outlet opening eannot be passed through its inlet opening.

In a known bag of this kind, the filling tube is attached through its entire length to the upper edge of the bag, and the two ends of the fiiling tube are in alignment with each ether, and constitute the inlet and the outlet opening, respectively. The inlet opening lies in a part of the side edge of the -bag adjacent to the upper edge.

The intention of this known construction is that the filling tube, when compressed -by the rising filling materia1 during the illing process, Wili be closed off in such manner that the bag may only be opened by making a hole in the side wall. Thus, as long as the walt of the bag is undamaged, one rnigbt be sure that no material has been removed from the filled bag. However, it has been found that this intention is not entirely realized in praetice.

When using the known bag, t is indeed impossibie for an unauthonized persen to remove materiai from the bag by drawing the filling tube out of the bag through the inlet opening, for instance by means of a hoek, rernoving matenial through the filiing tube, and replacing the filling tube into its normal position within the bag. However, it has been found possible to open up the filling tube and its outlet opening, for instance by means of a stick, so that material may be removed through the filling tube.

It is the object of the invention to provide an irnproved bag, in which the abovennentioned disadvantage is eliminated.

Another object of the invention is to provide a bag een structed in such manner that it is entirely impossible ior an unauthorized person to remove material from the bag without making a hole in the side wall A further object of the invention is to provide a simple and reliable method for producing a bag of the abovementioned kind.

Acoord-ing to the invention, a tube closed at one of its ends is attached exclusively with its ends to one of the edges of the bag, and eommunicates through an opening in its side wali with the interior of the bag.

Whereas, in the kno=wn construction, the filling tube is connected through its entire iength with the upper edge of the bag, so that the inlet opening, whioh is kept open by its connection with the side edge of the bag, the compressed fiiling tube, and the compressed outlet opening are in alignment with each other after the defor-mation of the filling tube by the filing material, the invention makes use of a tube of whieh the entire part between the ends is movable with respect to the wall of the bag. The part of this tube between the open end and the opening provided in the side wall constitutes the filling tube proper; the rernaining part of the tube on1y serves -to prevent the lateral out-Iet opening from being passed through the inlet opening.

Before the fillin-g material is supplied to the bag, the part between the ends of the tube is spaced at some distance from the edge of the Ibag to which the ends are attaehed. During the zfilling process, the part between the ends of the tube is moved towards said edge, and pressed against the same, whereby the tube is elosed oi. After that, the inlet opening, the eompressed filling tube and the outlet opening are not in alignment with eaeh ot-her any more, nor can they be brought into alignment from the outside.

In a preferred embodiment of the invention, the tube has initially a V-shaped axis, and the opening the side wail is provided at about half the length of the tube.

In a suitable method for producing the bag aceording to the invention, a tube made of a thermoplastic material is folded along a line inciined with respect to the axis of the tube so as to obtain a V-shape, after which the tube is sealed at both ends to one of the edges of the bag, a separating foil being inserted in the tube at one of its ends during the sealing process.

In order to aceelerate the production, the tube ends may be sealed to the edge of the back in the sarne step wherein the said edge is closed.

The invention Will be more fully expiained by reference to the accompanying drawing, showing a preferred embodiment.

In the drawing:

FIG. 1 is a side view of the bag acoording to the invention wherein part of the front wa1l is broken away, and

FIG. 2 is a perspective view of the bag.

The bag shown in the drawing i1as walls 1, whieh define a cavity. The walls preferably are made of a thermopiastic synthetic material. Thi-s material may be reinforced and may eonsist, for instance, of paper covered with a thermoplastc layer. Of course, -other suitable materia-ls may also be used for the bag.

A tube 2, preferably made of -a thermoplastic synthetic material and closed at its end 3, is attached at both ends 3 and 4 -to the upper edge 5 of the bag such that the tube 2 is supported in the cavity defined by the bag Wail 1.

The tube 2 bas been =folded into a V-sbape along a line 6, in=elined with respect to the axis of the tube, and cornmunieates with the interior of the bag through a lateral opening 7, substantially in the middle of the line 6. Ths opening is substantially horse-shoe-shaped on both sides of the line 6. The opening 7 has been shown at the underside of the tube. However, as an aiternative, it would also be possibie to provide the opening 7 at the upper side of the tube, likewise directly on the line 6.

The part 8 of the tube Whieh is aecessible through the open end 4, oonstitutes the filling tube proper. The re maining part 9 of the tube keeps the part 8 in such a. position with respect to the upper edge 5 of the bag that the filiing material exerts a lateral foree on the part 8 during the fiiling process, whereby this part is pressed against the edge 5.

Since the distance between the closed end 3 of the tube and the outlet opening 7 is smaller than the distanee be tween the ends 3 and 4, the portion 9 of tube 2 also pre vents the opening 7 from being passed through the inlet opening 4, whereby material cannot be removed from the bag through the filling tube.

If both the bag wal1 1 and the tube 2. are made of a thermopiastic material, the tube 2 may, after having been folded along the line 6, be sealed with its ends 3 and 4 to the upper edge 5 of the bag. Since the end 4, intended to operated as an inlet opening, must be kept open, a separating foii is inserted in the tube at this end. If the bag, and the tube are made of polyvinyl chloride, the separating foi1 may eonsist of polyethylene. The tube 2 may be sealed to the edge 5 in the same sealing step wherein the edge 5 is elosed.

The tube part 8 may be provided with a vacuum opening (not shown) through which a vaeuum is generated in the bag during the filling proeess, in order to acceierate filling. 

1. A BAG COMPRISING BAG WALLS DEFINING A CAVITY AND AT LEAST ONE EDGE, AND A FLEXIBLE TUBE OF V-SHAPED IN SAID CAVITY, SAID TUBE HAVING OPPOSITE ENDS ONE OF WHICH IS CLOSED, SAID TUBE BEING ATTACHED TO ONE OF THE EDGES OF THE BAG, SAID TUBE BAG BEING FOLDED UPON ITSELF ALONG A DIAGONAL LINE INTERMEDIATE THE ENDS OF SAID TUBE WITH AN INTERMEDIATE COMMUNICATION OPENING IN SAID DIAGONAL FOLD LINE. 